This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this project is to examine the link between brain development and development of lateralized behavior in capuchin monkeys from birth to early adulthood. Little is known about Cebus brain development and corresponding behavioral and cognitive development, outside of the fact that this species displays unusually fast postnatal brain growth and motor skill development. This extended period of postnatal brain development provides for the possibility of behavioral experiences to influence neural development and organization. The present project will provide important data about the normal maturation of Cebus brains and the role of experience in influencing neural organization. We will use magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to examine changes in morphology and topography of the corpus callosum as a result of long-term experience with cognitive and motor tasks. Brain development will be quantified by obtaining structural MRI and DTI at 6 month intervals, from the age of 1 week to adulthood. We will map the anatomical connectivity of the corpus callosum in capuchin monkeys in vivo using DTI. Various gross motor and fine motor assessments (including lateralized behavior) will occur weekly in these same individuals. Gross motor and fine motor assessment will follow the Mullen Scales of Early Learning. Individuals will also be characterized for hand preference while performing several motor tasks, including grasping, bimanual feeding and a coordinated bimanual task. As most studies of early experiences and the resulting effects on neurological development in primates have focused on adverse social experiences, our proposed research will provide a unique way to examine neural connectivity involved in motor learning. We will evaluate whether lateralized and non-lateralized subjects differ in the functional anatomy of the CC. We hypothesize that lateralized subjects will show differences in the organization of the CC, especially in anterior regions (projections to prefrontal, premotor and supplementary motor, and motor cortices).